Preheat oven to 300°F. Place 6 ramekins on a towel set in a roasting pan at least 3 inches deep. Set aside.

In a large saucepan, stir together cream and sugar over medium heat until very hot.

In a medium bowl, whisk together egg yolks, Irish cream, and vanilla until combined. Slowly add 1/3 of the hot cream, whisking constantly until incorporated. Stir in the remaining hot cream.

Divide custard between the ramekins. Then fill roasting pan with boiling hot water to come halfway up the sides of the ramekins. Bake in preheated oven until set, 50 to 60 minutes.

Remove ramekins to a wire rack and allow to cool to room temperature, about 1 hour. Cover, and refrigerate until cold, about 4 hours. Custards may remain refrigerated until ready to serve.

Unwrap the custards and sprinkle about 1 teaspoon of superfine sugar onto each. Gently shake the custards so the sugar coats the entire top surface, then tip the custards to a 45 degree angle and shake off excess sugar.

Using a small hand torch, melt the sugar by making short passes over top of the custards with the flame not quite touching. Continue melting the sugar until it turns deep brown. Once the sugar has melted and turned to caramel, the cold custard underneath will harden the sugar into a crispy crust. Serve immediately.